1. Field of the Invention
The present invention relates to a speaker, more particularly to a driver for driving a speaker.
2. Description of the Related Art
A permanent magnet and a diaphragm with a coil are used as a driver for speaker in prior art usually. By the magnetism that generates by the electrified coil is the same as or the different from the magnetism of the permanent magnet, the repulsion or the attraction will cause the diaphragm to generate a sound.
The structures of the driver that has a rare earth magnet therein use the rare earth magnet to replace the permanent magnet and reduce the chamber as disclosed in Taiwan Patent 375346. Even though the change shrinks the chamber but still generates the same heat. Because that the heat transmits by air in this prior art patent and the holes for airflow not communicate to each other, the heat will gather up at some place. The heat cannot transmit through out the shell efficiently and causes the temperature inside the driver rose. The diaphragm will deform in the high-temperature environment for a long period and shorten the operation period of the speaker.
As aforesaid, there is a disadvantage that needs to improve in the speaker of the prior art.